Process of concentrating ores



UNITED STATES PATENT- FFIcE;

CARRIE J. EV ERSON, OF CHICAGO, ILLINOIS.

PROCESS OF CONCENTRATING ORES.

SPECIFICATION forming part of Letters Patent No. 348,157, dated August 24, was.

Application filed August 29, 1885.

Ores; and I do hereby declare that the following is a full, clear, and exact descriptionthereof.

The discovery which forms the basis of my m invention is that metals and metallic substances in a comminuted state will unite with compounds of fats or oils and acids, and that such compounds will not unite with comminuted quartz or other rocky gangue. The es sential feature of the method which constitutes my invent-ion, therefore, consists in commingling with pulverized ore a fat or an oil, either ani'mal, mineral, or vegetable, or a fatty constituent or acid of an. animal or vegetable fat or oil, or any constituent of a mineral oil, to-

gether with an acid, either mineral or vegetable, or a soluble neutral or acid salt,-for the purpose of effecting a union of the free metal or metallic portion of the ore with such admixed material, whereby the same may be retained in the subsequent separation of the quartz or other rock therefrom by washing'or other suitable mcans. v

The invention is more specially applicable to the treatment of ores in which the metal or metallic portion is mixed with quartz or other rock as distinguished from the mixture of mineral with clay, though it is applicable to ores containing alumina, together with quartz or other rock, to the extent of permitting the removalv of the silica or sand. 1

The operation of concentration as a whole, or in its practical form as applied totthe sep aration of rocky mineral ores, involves the reduction of the quartz or other rock containing the mineral to a powder, the addition thereto of the fat or oil and acid or salt, and the subsequentremoval of the gangue.

If my invention is inapplicable to any particular rocky ores or class or classes of-roeky ores, or to the concentration of any particular metal, such limitations are not now known to me. Its commercial value, however, will prob; ably be restricted to its use in connection with ores bearing the precious metals, such as gold, silver, and copper.- I

Among the ores upon which I have operated antimony, arsenic,

Serial No. 175,665. (Spec-intone.)

successfully by means of my invention are the following: Ores containing nat ive gold and silver, kerargyrite, argentite, argentiferous galena, and a variety of double and otherwise compound sulphides of silver, with copper, and other base-metal sulphides. I'h'ave also operated successfully upon pyritic -ores, white, yellow, green, and .intermediate'shades, having variable constituents of iron, copper, arsenic, and sulphur, and mostly aurifcrous, and having variable proportionsof such constituents. I have also operated successfully upon ores containing tellurides of gold, silver, and lead, and others containing the oxides and carbonates of copper and the carbonate of lead. All the metals or metallic mineral portions of these ores are acted upon by the admixture described, in such manner as to permit the rocky gangue to be removed by a washing process, after which the several metals may be separated by theusual' means.

In putting my invention into practice any fat or oil, and any acid, either mineral or vegetable, or any soluble neutral or acid salt, or

any compound of fats and oils with appropri-' ate acids, may probably be successfully employed, at least such is the case with all of these agents with which I have so far experimented. I have used petroleum and one of its several constituents-namely, parallineoils-also Iallow, (m'elted,)'lard, lard-oil,

red-oil, (impure oleic acid,) cot-ton scedoil, caster-oil, sperm-oil, and linseed-oil, and some combinations of these with each other.

The acids which I have employed are sulphuric, hydrochloric, .uitric, acetic, oxalic, tanuic, and gallic. I have also used the followihg salts, to wit: the sulphates phosphoric,

and chlorides of sodium, zinc, and copper, and

the double sulphate of pot-ash and alumina: The selection of the appropriate agents will, however, be largely determined in the practical working'of my invention by the considcration of economy, which will obviously exclude the greater number of those above enumerated.

A reasonably cheap and practicable use of my invention will be as follows, the quantity named being suitable for laboratory 'use and the character of the ore specified, being substantially that of an ore upon which I have successfully operatcd'by the preparation and in the manner hereinafterdescribed;

Take an ore assaying twelve ounces per ton in silver and containing forty-eight per cent.

silica, 6.3 per cent. zine,'1.5 per cent. copper, fifteen per. cent. iron and aluminium, 6.5 per cent. lead, 14.18 per cent. sulphur, 7.1!) per cent. arsenic. Of this ore take four (l) ounces byweight in pulverulent form, prepare a mixture containing sulphuric acid, cotton-seed oil, and water, in all about twelve fluid drains, of which ten drams are of water and about two drams are acid and oil in the proportions of fifteen parts of the oil and two parts of the acid by measure. fluid mixturethe acid and oil are first mixed with each other, the acid being added to the oil very gradually, so that thetemperatu re will not rise above 120 Fahrenheit. The stirring in of the acid should be thorough, as it tends at first to gravitate to the bottom. After a few hours; in a summer temperature, the mixture will be ready for use, and, preferably, in such a temperature should not be prepared long before using, though if it should have stood long enough to solidify it should be gently heated before adding the water thereto. In winter or in air-tight vessels it may be kept for a number of weeks or even longer, arid then rendered fit for mixing with water by heating gently when required for use. The water may be advantageously added in install ments of about three equal parts, and the mixture stirred after each addition of water until it stifi'ens. Aft-er stirring in the entire quantity of water the compound is added to the ore, the proportionsof ore and compound being chosen r with a viewfto producing a stift'inass after the materials have been incorporated, such proportions being therefore variable in different cases with this end in view. The stirring or incorporation of the ore with the liquid should of course be thorough for the purpose of bringing the mineral into contact with the oil and acid as completely as possible, and after such incorporation the mass isthen in condition for the washing out of the quartz by the action of water which will be applied 'to the mass in sufiicient quantities for this purpose. The

washing should promptly follow the mixing, and in this operation the mass be opened out or broken up and thoroughly stirred in the water, in order that the sand or quartz may be freed and carried away. In treating so small. a bulk as above specified the mass may be squeezed repeatedly in the hand in a basin of water, the substance so manipulated being expressed between the fingers each time it is squeezed, and thus made to expose new surfaces to the water from which the sand will be detached, so as to fall to the bottom of the basin. In practice upon large masses any vessel having an outlet or outlets at its bottom for the escape of the water and sand will be suitable for this operation of washing, and mechanical means will of course be employed to break 'up the mass. The concentrated mineral will accumulate in a pasty mass or lump or lumps and will contain the metallic portion In making this of the ore, together with the hydrated oil'and acid, which latter may be removed by heating and afterward roasting, or by other suitable means. The use of petroleum or of a constituent thereof, either by itself or in combination with tallow, (heated,) cotton-seed oil, or other fat or oil, will be even less expensive.

\Vhen petroleum or a constituent thereof is used the oil should desirablybe first mixed with the ore, then water added containing a suitabie amount of free acid or a soluble neutral oracid salt, the quantity of water being ample for the washing-out operation, which is to follow, and the quantity of acid suflicient to cut the sand away from the otherwise cohering mass. In the case of petroleum or its constituent, parafiine-oil, one or two fluid drains of acid to one gallon) of water is sufficient for this purpose. The petroleum which I have used was 30 Banme, and'I have found three fluid drains of oil abundant for properly moistening two ounces of heavy. ore, or in the ratio of about a barrel of oil to the ton of ore, the amount being, of course, variable with the relative bulkiness of the ore.

In the use of petroleum, or of a liquid constituent thereof, like paralline-oil, the condition of the concentrated mass is more liquid than when a vegetable or an animal oil or a fatty constituent thereof is used, and a some- .what different means or method should be employed for removing the sand. In practice, the concentrate, after thorough agitation of the mass and detachmentof the sand, will in this case be preferably removed by means of a constant overflow of water from a washingontvessel, by which overflow the concentratev will be floated oil. Devices and methods now ,well known in wet separation of ores will be suited to this part of the operation, bearing in mind that the sand and mineral are merely transposed or their relative positions are reversed, because the sand is heavier than the mixture of mineral, oil, and acid. A proper selection of devices for this purpose will be apparent to those skilled in the wet separation 'of, ores. After removing the quartz or rock by washing or any suitable means the mineral may be roasted, in which operation the water, if present, will be dispelled, the oil will burn out, and the acid will be decomposed and eliminated, in the case of sulphuric-acid, which will commonly be used, by conversion into sulphnrous-acid gas, which passes off. In case fixed oils are used the mass may be allowed to stand until the water has run off. To hasten the operation of removing the waterithe mass may be heated, say, to about 212 Fahrenheit or less, whereupon the water will generally be promptly freed and may be poured bit or it may be evaporated. The operation of smelting is facilitated by the presence of the fat acting simply as a fuel. I

The disposition made of the mineral or metal after concentration whether by roasting and subsequent smelting or by smelting without previous roasting, or otherwise, belongs to the after treatment and is notmaterial to my present invention.

also according to the kind of ore to be treated; and the manipulation ,of the substances employed may be varied from that above set forth in either formula given. These matters may be determined in individual cases'by the operator; and I do'not, therefore, restrict myself to any particular proportions of the substances employed, though I have above indisalt must he added to. form the coagulnm. 1.

cated proportions of certain acids and oils by one of the other of which practical results may be obtained upon almost all-varieties of ores.-

It is also not essential to my inventionfthat the acid" or salt employed with a vegetable oil be added to the oil'before the incorporation of the oil with the ore, as it is entirely practicable, at least in most, and possibly in all, cases, to first mix such oilwith the ore and thereafter add the acid, use of petroleum.

I am aware that it has been proposcdin a patent to Tunbridge, No. 228,00l, dated May 25, 1880, to recover finely-conmiinuted metal held in suspension in water by the use of soap or a saponaceous compound formed by a partial or imperfect blending of an alkali or an alkaline salt with a fat or an oil. The action of the soap or saponaceous compound when difi'used through hard water containing the metal in suspension is to'-form with the lime salt in the water a coagulum in which the particles of metal are enveloped and by which they are held during a subsequent removalot the water. When the water is soft a lime disclaim the use of any substance in connection with the fats and oils capable of saponifying them. I also disclaim themethod set forth in said Tunbridge patent as' being en-. tirely dissimilar to that herein claimed. Said as set forth in the Tunbridge method is stated in said patent to consist in first depriving the water ofas much earthy non-metallic matter as possible, .this being efl'ected by any of the ordinary methods in use for that purpose, such as letting it stand until the earthy matter precipitates. My invent-ion, on the other hand, has reference solely to the separation of metal or metallic min-- eral from earthy non-metallic matter, (rocky gangue,) and not to its subsequent separation 'from water. In the practice of my method, moreover, the metal or mineral and nonme in the first instance mixed with the fator oil, and the non-metallic matter isaft'erwardsepa arated 'from'themetal or mineral by the peeu liar action 'of the acid or soluble neutral or acid salt operating in the presence of water to.- detach the 'gangue from the mass. With the understanding that I am not 'rcA stricted in the matters mentioned, I claim; broadly- 1; In the separation of pul'verulent ores containing rocky gangue, the method at treatment herein described, whichiconsists in mixing with such pulverulent ore a fat 'or an oil 70 or a constituent thereof, an acid or soluble neutral or acid salt,'.and water, finally breaking up the mass to allow t-helsand to separate therefrom.

of separating metals ormetallicminerals from or an oil or a constituent thereof with pulverized ore and washing 'out the gangue with.

.or acid salt. I V

In testimony that I claim the foregoing as my invcntion'l afiix my signature in presence of two witnesses. i

. 'CARRlEJ. EVERSON.

- Witnesses:

M. E. DAYTON, j 1

ELANAGHEN.

tallic matter (rocky gangue) are together and 2. The method, substantially as described rocky gangues, 'whicheonsists inn1,ixingafat water containing an acid or a soluble neutral 8o 

